The fabrication of a prosthetic socket typically occurs either in a local prosthetic clinical facility or in a commercial fabrication facility. The fabrication in a local prosthetic facility is very patient-specific and one-by-one; current methods are labor intensive and require highly skilled craftsmen and prosthetics. Prosthetic sockets made in such facilities typically fit the patient quite well, at least in a conformal sense, but can be deficient in terms of adjustability.
The fabrication process in a prosthetic facility is typically done completely in-house, and will now be elaborated on to convey a sense of its complexity and one-by-one character. The process begins with a prosthetist evaluating a patient's condition and needs, and taking measurements of the patient's residual limb. The prosthetist then casts a negative mold of the residual limb with casting tape. The resulting negative mold is filled with Plaster of Paris and allowed to harden. The negative cast is then peeled off to reveal the newly formed positive mold. The prosthetist may then modify the positive mold in an effort to create a form that best supports the creation of a limb socket that distributes pressure optimally on the residual limb when the socket is worn. The prosthetic socket, itself, is then built up by laminating layers of polymer material over the positive mold. Finally, the positive mold is broken and removed from within the fabricated socket, and the prosthetic socket may then be cut or further modified to better fit the residual limb.
Additional steps of the prosthetic socket fabrication process may include making and integrating flexible inner liners, locking mechanisms, alignment mechanisms, and other components, to create the final product. When fabrication of the socket is complete, the socket is typically tested on the patient for fit and for the patient's sense of how it feels and works. Although a few minor modifications of the socket are possible at this stage, such modifications are very limited, and the shape of the socket at this stage is the key factor in determining how well the socket will fit the residual limb and, thus, how comfortable the patient will be when wearing the prosthetic. As the ability to modify the shape and fit of the socket after fabrication in order to better accommodate the residual limb is very limited, it is common practice to make a number of “check sockets” or “diagnostic sockets,” from which the best option is chosen as the final product for the patient.
Various aspects of this conventional prosthetic fabrication process, as practiced in local prosthetic clinics and shops, are less than satisfactory. The central role of physical molds in the fitting process and the transfer of size and shape information from the residual limb to the final prosthetic socket product is a limiting technological factor. The fabricating process itself can take a month or more, and is an inexact process. And although the finished prosthetic socket product may be apparently quite satisfactory at first, it is still substantially fixed in form and cannot be easily modified, if at all.
The residual limb itself, however, is not fixed in form. In fact, the residual limb often changes shape and condition radically, both in the short term and the long term. First of all, even if a prosthetic socket seems to fit perfectly in a prosthetist's office, the socket may rub or place pressure on the patient's residual limb during daily activity over the days and weeks that follow. Additionally, patients often lose or gain weight rather quickly as a result of their amputations, thus causing the residual limb to grow or shrink. Similarly, as patients use their residual limbs with their prosthetic devices, they may build muscle and/or portions of the residual limb may change shape due to stresses placed on it during use. Finally, as the patient ages, the residual limb will continue to change, in response to continued use and environmental conditions. Using currently available techniques for making prosthetic sockets, any time a significant change is needed in a socket for a patient, the only solution is to start the process again from step one and make a brand new socket.
In a commercial prosthetic fabrication facility, prosthetic sockets are made at a larger scale with at least some aspects of modern assembly methods. Typically, however, even such commercial facilities use manufacturing techniques that are very craft-like and are quite time and labor intensive. Importantly, sockets are not made for specific patients, but rather in a limited range of sizes, with limited sizing and configuration options. Even with adjustability options, typical commercial sockets still remain substantially fixed in shape and circumferential dimensions, particularly at their distal end. As described above, residual limbs and patient needs can change significantly over time, and the adjustability options in commercial prosthetic sockets are often not up to the challenge.
Based on the shortcomings of currently available prosthetic socket manufacturing techniques described above, it would be advantageous to have improved techniques for making prosthetic sockets. Ideally, such techniques would facilitate the manufacture of highly customized prosthetic sockets tailored to the specifics of each patient, while also allowing for larger production, scalable manufacturing. These manufacturing techniques would also need to provide prosthetic sockets of very high quality, durability, and ideally adjustability. Various embodiments of prosthetic sockets that may lend themselves to the manufacturing techniques described herein are described by the assignee of the present application in U.S. patent application Ser. No. 13/675,761 (Pub. No. US 2013/0123940), filed on Nov. 13, 2012; and Ser. No. 14/213,788, filed on Mar. 14, 2014. Both of these references are incorporated in their entireties herein.
Improved prosthetic socket manufacturing methods would also ideally facilitate the process required for prosthetists, physicians and most importantly patients. Such methods should reduce the amount of time required for a patient to receive a finished prosthetic socket from the first visit to a physician's or prosthetist's office. It would also be ideal if physicians and prosthetists could easily order and quickly receive prosthetic sockets and if patients did not have to undergo multiple fittings, adjustments and the like at the physicians' or prosthetists' offices. At least some of these objectives will be met by the embodiments described herein.